Field of Invention
The present invention relates to an antenna, and more particularly to an antenna with an anti-interference arrangement, wherein the anti-interference arrangement prevents electromagnetic wave signals received or generated by the antenna from being interfered by the nearby electromagnetic radiation frequency or the stray radiation frequency, so as to enhance the anti-interference ability of the antenna.
Description of Related Arts
Industrial Scientific and Medical (ISM) Bands are designated by ITU-R (ITU Radio-communication Sector) and are unlicensed radio bands reserved internationally for the use of radio frequency (RF) telecommunications by institutions such as industry, science, and medicine institutions. During the use of these bands, the transmission power thereof must be restricted (usually lower than 1W) and must not be interfere with other frequency bands. Nowadays, these ITU-R opened frequency bands being used for microwave detection are mainly set at 2.4 GHz, 5.8 GHz, 10.52 GHz, and 24.125 GHz. In recent years, new frequency bands are frequently utilized for the application of microwave detection. For example, the application of 5G technology will cause a new frequency band being used for microwave detection in addition to the existing frequency bands being already used for microwave detection. It is known that there will be a mutual interference when two or more frequency bands are used closely. For the microwave detection as an example, when the 5.8 GHz of frequency band is used for human or object motion detection, such 5.8 GHz of frequency band will be inevitably interfered by the application of 5G technology. As a result, the interference of the application of 5G technology will cause the inaccuracy of the detection result from the 5.8 GHz of frequency band. As the 5G technology is rapidly well-developed recently, the 5G system will be more open and the application thereof will be widely used. It can be foreseen that the large-scale application of 5G technology will inevitably form a high speed based on 5G data network and will continuously expand more frequency bands in the future. In other words, the possibility of interference of the frequency bands for the microwave detection will be highly increased by the application of 5G technology. Therefore, it is urgent to improve the antennas with anti-interfering ability for the microwave detection. Accordingly, a conventional method for enhancing the anti-interfering ability for the microwave detection antenna is the suppression method by shielding external wireless signals, signal filtering, and software algorithm processing to suppress the interference. However, such conventional method can only provide limited anti-interfering ability for limited frequency bands. Therefore, a need exists for an antenna that enhances the anti-interfering ability to different frequency bands. It is to the provision of such an antenna that the present disclosure is primarily directed.